1. Field of the Invention
The present invention relates to a code changing method for an electronic music instrument with an automatic accompaniment function, and in particular to an improved code changing method for an electronic music instrument with an automatic accompaniment function capable of changing a code during a play in accordance with a tone of an electronic musical instrument before a new code is inputted for the next music play.
2. Description of the Background Art
As shown in FIG. 1, a conventional electronic musical instrument with an automatic accompaniment function includes a function input circuit 101 provided for outputting a signal corresponding to an automatic accompaniment function and automatic accompaniment style which are selected by a user; a keyboard information input circuit 102 provided for inputting a signal corresponding to a keyboard information of a code, (e.g., a chord) a melody, and the like which are selected by the user; a control circuit 103 provided for performing an automatic accompaniment function in accordance with a signal outputted from the function input circuit 101 and the keyboard information input circuit 103, a sound source circuit 104 provided for processing a sound signal outputted from a previously stored sound data in accordance with a control signal outputted from the control circuit 103; and a sound output circuit 105 provided for amplifying and outputting a sound signal outputted from the sound source circuit 104.
The operation of the conventional electronic music instrument with an automatic accompaniment function will be explained with reference to FIGS. 2 and 3.
To begin with, the control circuit 103 checks a signal outputted from the function input circuit 101 and judges whether a predetermined function (i.e., an automatic accompaniment function) is selected (Step 1). As a result of the judgement of the step 1, if the automatic accompaniment function is not selected, the step 1 is repeated. However, if the automatic accompaniment function is selected, the control circuit 103 checks a signal outputted from the keyboard information input circuit 102 and judges whether a predetermined code (e.g., representing a chord) is outputted therefrom (Step 2).
As a result of the step 2, if it is determined that a predetermined code (i.e., the chord) is not inputted to the control circuit 103, the control circuit 103 repeats the second step. If the code is inputted, the control circuit 103 checks a signal outputted from the function input circuit 101 (Step 3) and performs the automatic accompaniment function (Step 4).
That is, the control circuit 103 recognizes an automatic accompaniment style selected by the user and outputs a control signal in accordance with the automatic accompaniment style recognized by the step 3.
Thereafter, the sound source circuit 104 outputs a sound signal from the previously stored sound data in accordance with the control signal, and outputs the sound signal to the sound output circuit 105.
Thereafter, the control circuit 103 checks a signal outputted from the keyboard information input circuit 102 and judges whether a new code (a new chord) for an automatic accompaniment is inputted (Step 5). As a result of the step 5, if the new code is not inputted, the steps 4 and 5 are repeated. If a new code is inputted, the control circuit 103 processes a code change in accordance with the inputted new code.
Here, the code change process is performed as follows.
That is, after a music is played in a C major as shown in FIG. 3A, if the code information (i.e., representing a chord) in F major is inputted as shown in FIG. 3B, the control circuit 103 performs an automatic accompaniment following the newly inputted code information in F major.
Meanwhile, as shown in FIG. 3A, in a state that a music of a C major is played from the starting point to the Z-point, if a code information in F major is inputted as shown in FIG. 3B, the control circuit 103 performs an automatic accompaniment in the F major after the Z-point as shown in FIG. 3C.
Here, as shown in FIG. 3D, if the new code information is inputted while a music is being played, the previous music is slurred for a soft connection between the previous music and the newly inputted music. Here, a slur processing smoothly varies a high pitch difference in sound so as to continue the previous tone play.
However, the conventional electronic musical instrument with an automatic accompaniment function has disadvantages in that when a new code information representing a chord, for example, is inputted to change a music while the music is being played, an unusual tone is generated because the conventional code processing method is directed to changing the last tone which exists when a new code representing a new chord is inputted, so that there may be another tone which is different from the currently playing music.